Routing protocols have evolved over the years to match the growing complexity of computer networks. Routing protocols specify how routers in a computer network communicate and share information with each other. Routing protocols allow routers to dynamically learn about routes that may exist on a network, build routing tables and perform routing decisions. Some examples of routing protocols include Interior Gateway Routing Protocol (IGRP), Enhanced Interior Gateway Routing Protocol (EIGRP), Open Shortest Path First (OSPF), Border Gateway Protocol (BGP), and integrated Intermediate System-Intermediate System (ISIS).